It is conventional to prepare uncooked food, such as meet, fish, vegetables, etc. on manually-rotated skewer blades, but it is not convenient way for skewering because a cook has to carefully and periodically rotate the skewers. Moreover, it frequently happens that the food is not evenly cooked because all portions of food are not equally heated.
There a number of rotisserie apparatus of the prior art in which authors utilize mechanical devices, such as electromotor-driven gearboxes, wherein each skewer is mechanically attached to its individual gear. Examples of such apparatus are described in U.S. Pat. Nos. 3,442,202, 3,939,761, 4,154,154 and Canadian Patent No 2,070218. The rotisserie apparatuses, which are described in these patents, utilize a gearbox comprising a number of drive gears, wherein each drive gear is attached and exclusively dedicated to an individual skewer.
U.S. Pat. No. 3,442,202 describes the rotisserie apparatus having gearbox powered by an electromotor and containing linearly-positioned gear wheels sequentially transmitting rotation, therefore continuously rotating attached skewers.
The rotisserie apparatus depicted in U.S. Pat. No. 5,001,971 also utilizes an electromotor-driven gearbox providing some additional features, but having complicated design that is not suitable for ordinary BBQ or grill.
U.S. Pat. No. 3,939,761 describes the rotisserie apparatus powered by an electromotor and utilizing a drive chain for skewer rotation.
U.S. Pat. Nos. 4,154,154 and 5,715,744 describe the rotisserie apparatuses having gearbox powered by an electromotor and containing worm screw engaged with a number of gear wheels, wherein each gear wheel is connected to an individual skewer, therefore continuously rotating the skewers.
The rotisserie apparatus described in Canadian Patent No 2,070218 has the design similar to one utilized in U.S. Pat. No. 3,442,202. Unlike the apparatus of U.S. Pat. No. 3,442,202, it is a separate unit mounted atop a grill or BBQ.
Despite of advantage of skewer mechanical rotation, features of rotisserie apparatuses of the prior art are not satisfy to common cooking requirements, such as evenly cooking all parts and pieces of food.                To properly prepare food, so avoiding burning and undercooking, the programmable timer is required.        In the majority of cases, it is asymmetric position of food on the skewer. Therefore, if the skewer is continuously rotating with constant rotational speed, different parts of the food become unevenly cooked.        When pieces of food placed on different skewers have different size, shape and weight, rotisserie apparatuses, in which all skewers rotate with the same rotational speed, can not cook evenly all pieces of the food.        Sometimes in the process of skewing, it is necessary to manually turn (adjust) position of the skewer. If the skewers are firmly attached to drive gears, manual rotating of the skewers becomes impossible.        Also, the apparatus simplicity and its cost-efficiency are essential.        